Spark-plug



F. CARLSON. SPARK PLUG.

MPLICATLON FI LED JUNE 30, 1919- I PatentedDec. 14, 1920.

PATENT OFFICE.

FREDERICK ELIAS CARLsori, on NEW BRITAIN. CONNECTICUT.

SPARK-PLUG.

Application filed June 30, 1919.

T 0 all 10 ham it may concern Be it known that I, FREDERICK ELIAS CARLSON, a citizen of the United States, residing at New Britain, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Spark-Plugs, of which the following is a specification.

My invention relates to improvements in spark plugs, and the object of my improvement is to produce a spark plug that produces superior results by reason of having a plurality of sparks at each operatiomone or more of which sparks is over and adjacent a surface of insulating material, and involving thorough combustion, particularly at or adjacent the exposed surfaces of the spark plug, whereby is avoided the formation of soot and the deposit of carbon on the said surfaces and the spark plug can be run continuously and indefinitely without fouling.

In the accompanying drawing Figure 1 is a side elevation of a spark plug embodying my invention.

Fig. 2 is a plan view of the same.

Fig. 3 is a sectional view on the line 3-3 of Fig. 2 and on, an enlarged scale, the lower part that has the connection terminal and adjacent parts being omitted.

Fig. 4: is a plan View of the disk member.

Fig. 5 is a plan view of a modification of the disk member. 7

Fig. 6 is a sectional view corresponding to Fig. 3 of a structure in which is incorporated the modified form of disk member shown in Fig. 5.

My improved spark plug comprises a body 10 of metal of the usual form for the exposed portion that is screwed into the wall of the cylinder of an internal-combustion engine and which serves as the ground connection and a line connecting member 11 that is removably supported by the said body 10 in axial position comprising at the outer .end the line terminal 12, the line electrode 13 at the other end and connected electrically to the said line terminal 12, and the insulating structure 1 1 of porcelain extending along the middle and body portion.

The line connecting member 11 is substantially of the usual form or similar to a number of forms in common use, the line electrode 13 constituting the active element thereof that is positioned within the engine cylinder and comprising simply a piece of Specification of Letters Patent.

Patented 1 1. 1220.

Serial No. 307,653.

ring 20 of metal on the lower face that serves as one of the active parts, being generally 1n the form of a washer, a washer 21 of insulating material above the ring 20 that serves as the mechanical support for the said ring 20. and a backing washer of metal 22 on the upper face of the insulating and supporting washer 21 for receiving the upper ends of the rivets 23 that hold the parts together.

The main part 18 has a central hole 2 1 that is appreciably greater than the diameter of the wire 13 and is positioned concentric with the said wire 13.

The part of the hole 24 inclosed by the ring 20 serves as the active portion of the said main part 18 in cooperation with the op osed portion of the wire 13.

The ring 20, supported by the insulating washer 21, as mentioned, is smaller in diameter than the said insulating washer 21, and has the outer edge portion opposed to the inner edge of an outer ring 81 that is interposed between the outer edge portion of the said insulating washer 21 and the inwardly turned edge or rim portion 25 of the sleeve 19, being separated from the said ring 31 by a short radial space 26. The said outer ring 31 is thus incorporated in the sleeve 19 and is constructed and arranged. so as to serve as the active, contact port on of the outer, grounded electrode 15. The rim 25 serves as a holding flange to hold the parts together and the outer ring 31 serves as a lining therefor and proiects inwardly sli htly more than the rim 25.

The insulating and supporting washer 21 is made of mica and is of the right size to fit over the lower edge portion 27 of the cylindrical sleeve 16 of the body 10, and interposed between the same and the said edge portion 27 is a second washer 28 of mica or other suitable insulating material that ex tends over the back or upper face of the composite main part 18, opposed to the metal backing washer Q2.

In order to hold the insulating washer 28 and the main part 18 in position at the lower edge portion 27 I provide any suitable means, such as the sleeve structure 19 that has the body portion fitted over the cylindrical portion 16, the lower edge portion being turned inwardly to form the holding flange 25, and which has at the upper end portion an indented annular portion 29 that is spun or turned into a groove 30 in the periphery of the cylindrical wall 16.

In use, the sleeve 19 is electrically a part of the grounded electrode structurethat is grounded to .the engine structure through the body 10 and between this and the line electrode 13 is the annular structure 20 that serves as an intermediate plate to divide the spark so that there will be effectively two sparks, being in series.

Actually I find that there is one spark in the open space provided by the hole 24 around the wire 13 and in addition thereto there is usually more than one spark across the space 26, being a plurality of sparks, distributed around radially.

A spark plug constructed as described I find operates effectively for a relatively long period without becoming foul or thrown out of commission by reason of deposit of carbon.

In the structure shown in Figs. 5 and 6 there are two active intermediate rings or washers between the wire 13 and the outside washer 31 under the holding flange 25 of the sleeve 19, comprising the inner washer 20 opposed to the wire 13 and the ring or washer 20 exterior thereto.

. structurally the inner washer 20 is in the form of an eyelet rivet that borders the hole in the mica washer 21 and the second washer 20 is in the form of a ring of metal that is secured to the mica washer 21 by the rivets 23*.

By the use ofthe extra intermediate electrode ring there is obtained a greater distribution of the sparking effect.

I claim as my invention 1. A spark plug comprising a line electrode of wire and a grounded electrode for cooperating with the said line electrode having an active portion concentric with the said wire and separated from the said wire by a space, a ring of conducting material positioned in the said space, concentric with the said wire, and provided with a supporting washer of insulating material, the said grounded electrode having a body portion that has a threaded part for engaging with the engine cylinder and a reduced cylindrical part below the said threaded part, the said supporting washer being positioned in abutment with the end of the said reduced part, and a sleeve fitting over the said reduced part and having means for holding the said supporting washer in such position.

2. A spark plug as described in claim 1, the said sleeve having a rib and groove connection with the said reduced part and having an inwardly turned flange for engaging with the outer face of the said supporting washer.

FREDERICK ELIAS CARLSON. 

